Tag Archives: brain

Ray Kurzweil is an American author, computer scientist, inventor, futurist, and is a director of engineering at Google.

Summary

200 million years ago mammals evolved the neocortex. This allowed them to learn and think around problems, to develop new behaviour. Previous reptiles needed to ‘evolve’ new behaviour over thousands of years, but these early rodents could do so instantly. This helped mammals survive the cretaceous extinction event, and since then the neocortex has gotten larger and larger to enable high level thinking.

The brain is a series of ~300 million modules in hierarchies to work on patterns of data: to recognise, learn, implement a pattern. For example a series of modules might look for the crossbar part of an “A”, then a higher module would decide it is an “A”, then the word, sentence etc. It can also work in reverse, using context of higher levels (the rest of the word) to lower thresholds as if asking “I think it is: could this letter possibly be an A?”. This is similar to a Hierarchical Hidden Markov Model, being used in AI to understand language.

In the future hybrid thinking will evolve: combining human and computer thinking. Google will understand language more than just series of keywords, and could anticipate user problems and keep them up to date on research of interest to them. Ray also predicts that nanobots could interface with out neocortex and connect it to ‘the cloud’ – to massively expand our brainpower using an external computer network. This will expand our neocortex: and remember how powerful it was last time mammals developed their neocortex… This time we will not be restricted by the architecture of our heads – there could be no limit.

My Thoughts

The history of the neocortex is one of the better descriptions I have heard. The models he describes are easy to understand for the layman and also useful enough to apply to reality.

His comments on the future seem a bit too sci-fi though. It isn’t that this won’t happen, but he doesn’t really describe how or why. Thoughts of the AI singularity and similar ideas have been knocking around human culture for 50 years, constantly just around the corner. We are no doubt closer now than before, but the nanobots and ‘brain extension’ he talks about are a long way away. Even if AI is ready for this advancement, medical understanding of the brain is still too far away to connect us into computers.

Jeff Iliff is a neuroscientist at Oregon Health & Science University, previously doing research into brain cleansing mechanisms at University of Rochester Medical Centre.

Summary

We spend roughly a third of our lives asleep, but it is not clear why the body needs it. 2,000 years ago it was proposed by Galen that the brain sent fluids around the body, and these were returned during sleep to rejuvenate the brain. The idea is ludicrous today, but Jeff still suggests brain activity could account for our need of sleep. The brain uses 25% of our energy but takes only 2% of our mass. The first major issue in any body organ is nutrient intake – which is satisfied by the circulatory system and the network of blood vessels surrounding the brain. The second issue is waste disposal, which in most organs is done through the lymphatic system. The lymphatic system transports waste from the cells to bloodstream, however it does not exist in our heads so cannot be used by the brain. So how does the brain dispose of waste? This was where Jeff started tackling the problem.

The brain is surrounded by cerebral spinal fluid (CSF). Waste is dumped into CSF, which is then transported to the blood. To help this, CSF is pumped along the outside of blood vessels – to clean and penetrate deeper into the brain wherever blood vessels are. However, this action only happens while we sleep. As we sleep the brain cells contract, to open up spaces between them and let the CSF flow more easily. Ironically, this idea of fluid rushing through the brain is similar to Galen’s ideas thousands of years ago.

What sorts of wastes need to be cleaned? One is Amyloid Beta – which is made all the time, but an inability to clear them away is thought to be a factor in getting Alzheimers disease. Studies have found that a decrease in sleep is associated with an increase in Amyloid Beta in the brain.

While we sleep, our brain never rests. It is busily cleaning this important machine, and possibly preventing serious issues later. By understanding these housekeeping functions today, we may be able to prevent serious diseases of the mind tomorrow.

My Thoughts

Interesting talk and interesting research. I learnt a bit about brain activity, sleep and Alzheimers all at once. He summed up a lot in less than 12 minutes.

Henry Markram is a Professor at Swiss Federal Institute of Technology in Lausanne and director of both the Blue Brain Project and the Human Brain Project.

Summary

Henry’s goal is to build a realistic computer model of the human brain. He has already succeeded at a proof of concept – building a rodent brain, and now wants to scale it up. The reasons we need this model are

It is essential for us to understand our brain

We cannot keep doing animal experimentation

There are 2 billion people affected by mental disorder, and the drugs used to treat them are empirical. If better understood, we can develop better solutions.

So how does the brain work? One theory is that the brain builds its own version of the universe and projects this image around us. We decide the size and shape of most things around us – when we walk into a new room, 99% of the sizes, shapes, identities of objects are inferred by our brain. “I think therefore I am”. Henry’s talk will explore if a brain is capable of building such an elaborate model of the universe.

The brain took 11 billion years to form. The first big innovation was the frontal part to give instincts, but the big development for mammals was the neocortex. This dealt with parenthood and social interaction, and with humans it is much larger than mice and is still getting larger. The neocortex is covered in small modules of processing, and these are amazingly powerful. So much so that they kept increasing in number until they filled the whole skull, then started folding in on themselves.

Over the past 15 years, Henry’s team has been dissecting the neocortex – understanding the communications between neurons, cataloguing each piece, and building a 3D digital model of each neuron. By putting each of these models together and understanding the connections between them, you can rebuild the neocortical column. Each neuron intersects others in millions of places, creating a synapse that allows communication between them. This communication is in the form of an electrical charge, which interacts with a synapse to release chemicals to stimulate the next neuron.

The equations to simulate communication between neurons are simple, and already known – but you need a very powerful supercomputer to simulate the whole brain. They have done this, and although they haven’t fully trained the brain they can stimulate it with an image of a rose and see which neurons are triggered. They hope to analyse it deeper, and map these neurons to physical coordinates so we can actually see how the brain sees the universe around it. This would be an amazing step in the evolution of the universe – a time when the one brain can see the world projected by another, and in effect becomes self-aware.

Speaker: Jill Bolte Taylor – a neuroanatomist interested in how the human brain relates to schizophrenia and severe mental illness. She is also an author, having published books on her stroke “My Stroke of Insight” and ranked by Time magazine as one of the 100 most influential people in the world. Full Bio at http://en.wikipedia.org/wiki/Jill_Bolte_Taylor

Length: 20:11

Summary

Note this talk is an animated story of Jill’s experiences during a stroke – where one hemisphere of her brain was ‘switched off’. This summary cannot do the full talk justice – if it interests you, watch the full video.

Jill Bolte Taylor starts by trying to work out what makes her brain different from her brother’s – who is schizophrenic. She elaborates by bringing a real human brain to the stage – showing it is divided into 2 distinct halves, with minimal connection between the two. Each half functions differently:

Right Hemisphere is a parallel processor. It focusses on the current moment, using pictures and learns through kinaesthetic movement. It is well connected to senses to build an understanding of what is happening at the moment. It connects us with the world around it.

Left Hemisphere acts as a serial processor. It thinks linearly and methodically, looking at the past and future. It picks through the details of the current time – arranging and sorting these, and connecting them to the events of the past and future. It thinks in language and words. It looks as us as an individual, isolating us from the world.

Jill had a stroke which disabled the left side of her brain – waking up to a throbbing pain behind her eyes similar to ice cream headache. She used an exercise machine while on a stroke, and focussed on how strange her body looked – as if she was out of her body. She noticed that every movement was slower, laboriously focussing to execute every movement. She couldn’t work out where her body ended and the rest of the world began, thinking about the energy of the world around her. Soon her left hemisphere recovered and started to realise that she was in danger, before dropping out again. During the stroke, she was disconnected from her normal brain chatter – the stress and emotional baggage.

When she realised she was having a stroke, she decided to study her brain from the inside. She tried to read her business card, but her vision as broken to ‘pixels’ – and she couldn’t differentiate it from the background. She was having difficulty picking out objects in vision – couldn’t read the numbers, couldn’t keep track of the numbers she had dialled. When she eventually got the phone working, she couldn’t understand the other end, nor speak clearly herself. Eventually an ambulance was called, and she blacked out.

When she woke, she was alive and the stroke was over. She thought back on the stroke as a moment of Nirvana – where she felt connected to the world, and that her spirit was larger than her body. She started to wish everyone could have that moment where their left brain switched off.